1. Field of the Invention
This invention relates to pipe clamps for holding various types of pipes.
2. Description of the Prior Art
Various types of pipes are used in automobiles and resin holders called pipe clamps are conventionally used to fix the pipes to the automobile body side. The pipe clamps are usually formed integrally of a resin such as polypropylene. Pulsation of a fluid flowing through the pipe sometimes vibrates the pipe clamp. The vibration needs to be prevented from being transferred via the pipe clamp to the automobile body side. In use of the pipe clamp formed integrally of the resin as described above, however, the transfer of vibration is difficult to be prevent.
The prior art has developed a pipe clamp in which a soft resin portion with the ability to absorb vibration is stacked on a pipe holding portion thereof so that the pipe overlaps the soft resin portion. However, since the pipe is held by the soft resin, a holding force against the pipe is inevitably reduced although the soft resin is effective for the absorption of vibration. Consequently, the pipe deviates from its normal state to be held in an inclined state when the pipe clamp is subjected to an external force after having been attached to the pipe.
As a countermeasure, it is proposed to individually form a portion holding the pipe and a portion fixing the pipe to the body side, and to connect these portions by a soft resin portion. As a result, the vibration transferred to the body side could be absorbed by the soft resin portion and a sufficient strength could be ensured in the portion holding the pipe or fixed to the body side.
However, when the pipe clamp comprises two separate members, that is, the pipe holding portion and the pipe fixing portion as described above, connecting the two portions by the soft resin portion is important. An insert molding could be one of most effective measures. The pipe holding portion and the pipe fixing portion need to be integrated previously when these portions are set in a die. The integrating work is troublesome. Moreover, both portions need to be integrated through a space provided for forming the soft resin portion. In this case, setting the two portions in the die with the portions being positioned causes troubles, resulting in an increase in the working time. Thus, the above-described problem is very important in achievement of automated forming of the pipe clamp.